Multi-needle sewing machines



Aug. 15, 1961 K.P0LLME|ER 2,996,023

MULTI-NEEDLE SEWING MACHINES Filed July 14, 1959 Fig. 2

/Nve/v ro P States Pate 2,996,023 g MULTI-NEEDLE SEWING MACHINES Konrad Pollmeier, Bielefeld, Germany, assigner to Diirkoppwerke Aktiengesellschaft, Bielefeld, Germany, a

` corporation of Germany Filed Jnly 14, '1959, Ser. No. 827,037

Claims priority, application Germany July 30, 1958 4 Claims. (Cl. 112-100) 'Iltis invention relates to multi-needle sewing machines' provided with an apparatus for the placing of a quilt thread crosswise to the needle thread stitch rows at the upper side of the Work piece, and a thread drawing nger for receiving the excess thread occurring periodically in the quilt thread.

In a known multi-needle sewing machine of this kind the thread layer, swinging above the stitch plate is carried by a bearing bush guiding the material presser bar and rotatable in the machine head and on which a horizontal link engages with a ball joint. This is connected by a further ball joint to an arm which is iixed on a pivoting shaft extending longitudinally over the rear side of the sewing machine arm. This pivoting shaft is driven by the main shaft mounted in the hollow foot plate, via connections which extend upwards in the hollow stem of the arm and outwards through an opening therein. On the said pivoting shaft there is also xed a thread drawing nger which can seize the thread in the intermediate space between two thread guide eyes.

In consequence of the large masses to be moved, which are formed by a plurality of pivoting levers and transmission members, this drive for the thread placer and the thread drawer scarcely suited for a sewing machine of the type described, in so far as the machine has to work without vibrations at high speeds. Also the arrangement of the exposed pivoting shaft for the transmission of movement from the driving shaft to the thread placer is unsuitable as, on the one hand the driving parts are easily soiled while the work piece also is exposed to the lubricant squirting around and coming out of the bearing places or the guide openings for the ba-rs and, in addition a smooth and artistic construction of the whole machine is not attained.

The present invention has as its object an apparatus for the placing of a quilt stitch and for the receiving of the excs thread occurring periodically, which consists of little moved and easily transferred parts, so that the sewing machine in consequence of the small mass forces runs free of vibrations at high speeds. Further, all driving parts are located within the sewing machine casing, in order to prevent the danger of the forcing of lubricant from the machine and in order not to detract from the beauty of the outer shape of the machine.

The invention achieves this desired result by means of a two-armed transmission lever rotatably mounted in the sewing machine head and set in swinging movement by rotation of the top shaft of the machine, one arm of which transmission lever is in driving connection with the thread placer and the other arm of which is formed as -a draw nger for excess thread or operates such a draw finger.

This two-armed transmission lever may be constructed as an angled lever, one arm of which serves as a thread draw nger and is linked to an eccentric drive arranged on the top shaft of the machine, =whilst the other arm engages a link connection connected to the pivot shaft of the thread placer. This link connection may for example consist of a bush arranged with its axis parallel to but spaced from the axis of the said pivot shaft, and a block slidable both radially and axially in said bush, which block is formed with an opening lying at right ploded view of the apparatus comprising the invention. l

As shown, the needle bar 7, which is mounted in the FIG. 1 is a part sectional view, in a longitudinal vertical plane through a sewing machine provided with an apparatus according to the invention;

FIG. 2 is a transverse vertical section through the machine on the line II-II of FIG. l; and' FIG. 3 is an exhead, is driven from the arm shaft 3 of the sewing machine, which shaft is rotatably mounted in the arm in A thread placer 13 yarranged over the stitch plate 11 andl A over the presser foot 12 co-operates with the needles 9,

10, the free end of this member being formed hook-like in order to s'eize the quilt thread D before the needles 9, 10. This quilt thread D comes from a thread guide 18 has a collar 21 (FIG. V3) to rest on the top end of' bush 20. -For'the purpose of adjustment of the outward swinging width of the thread placer 13, the pivot shaft 18 is formed furthermore with a pin 22 extending upwards from the collar 21 and arranged eccentrically thereto, on which pin is a split bush 24 running axial parallel to the pivot shaft 18 and formed integral with a further and parallel rotatable bush 23, adjustable about the pin 22 and fixed in adjusted position with the aid of a clamping screw in the split bush 24.

The rotatable bush 23 is provided with openings 25, 26 at opposite sides, and there is guided within it a cylindrical sliding block 27 which has a transverse opening 28 for receiving a sliding rod 29 extending from an arm 30 of a double-armed lever 31. This lever 31 is rotatably mounted around a bolt 32 which is fixed in the head 8 of the sewing machine in a manner not illustrated. The other arm 33 of the two-'armed lever 31 is linked to an eccentric strap 34 which for this purpose has two co-axial bearing eyes 35, 36 between which the said arm 33 is rotatably xed by means of a pivot bolt 37 (FIGS. l and 2). A pinching screw 38 in the arm 33 prevents movement of the bolt 37 in the lever.

The eccentric strap 34 houses a roller bearing 38 which surrounds an eccentric 39 which is rotatably mounted on the arm shaft 2 adjacent the crank 4, and is in driving connection with this crank by means of an extension 40 of the driving pin 41 of the crank.

The arm 33 of the two-armed lever 31 is extended beyond its link connection to the strap 34, and has a tapering part (FIGS. 2 and 3) forming a thread draw finger 42 which extends through an opening 43 in the tout side of the sewing machine head 8 to dorm a draw-finger 42 lfor the thread D, see FIGS. 2 and 3. Over this opening 43 there is located a U-shaped thread guiding plate 44 which is provided with an oblong hole 45 for the passage therethrough of the draw iinger 42, and for the xing of the plate on the head 8 by means of screws 46. The two side arms or webs 47, 48 of the thread guide plate 44 are formed with openings 49, 50 for the passage of the quilt thread D as it comes from the thread supply (not shown).

Patented Aug. 15, 1961 Before reaching the thread guide plate 44 the thread D is-guided over an adjustable spring tension (not illustrated). On the way to the thread guide 14 from the guide plate 44, the quilt thread D passes through a further tensioning device 51 (FIG. 2) bywhich an additional drag is produced in the thread D before it is fed through a guide eye 52 on the needle bar 7 and to the thread placer 13.

In operation, on rotation of the shaft 3, the lifting movements of the eccentric 39 transmitted to the two-armed lever 31, are transferred by means of the connections Z9, 27 and 23, to the pivot shaft 18 of the thread placer 13, which latter together with the quilt thread D, is swung forwards and backwards in a horizontal plane below the needles 9, 1G, whereby the needle thread loops on the upper side of the work piece are connected to one another in a cross-wise manner. At the same time the draw finger 42 takes up the loose quilt thread D between the side webs of thread guiding plate 44 during each return movement of the thread placer 13.

The amount of thread to be drawn out duringeach working movement of the draw linger 42 may be adjusted easily by varying the position of the `guiding plate 44 over the oblong hole 45.

WhatV I claim is:

1. In a multi-needle sewing machine having a supporting structure, van arm shaft rotatably supported on said structure, means for laying a quilt stitch thread crosswise between parallel rows of stitching comprising a thread layer, said thread layer adjustably attached to a vertical pivot shaft, a two-armed transmission lever mounted for rotation on said machine, oscillating means on said machine connected to one arm of said two-armed lever for oscillating said lever in timed relation with the rotation of said arm shaft, motion transfer means connecting the other arm of said lever to said pivot shaft for producing selected oscillatory movement of said thread layer in response to rotation of said arm shaft, a draw finger attached to said one arm of the two-armed lever, and thread guide means adjustably mounted on said machine adjacent said draw finger for positioning a quilt stitch thread in contacting relationship with said draw linger such that a selected amount of thread will be drawn out by movement in a selected direction of said draw finger. Y

v2. The device claimed in claim l wherein said oscillating means includes an eccentric mounted on said arm shaft, an eccentric strap positioned over said eccentric for translating rotary motion of said arm shaft into oscillatory motion, and pivot means connecting said strap to said one arm of said two-armed transmission lever for transferring oscillatory motion to said two-armed lever.

3. The device claimed in claim 1 wherein said motion transfer means includes a hollow bushing having opposite side openings therein, a block disposed in said bushing for axial and rotational movement therein and having a transverse opening, a sliding rod positioned through said side openings and said transverse opening, said sliding rod extending laterally from said other arm ofsaid two-armed transmission lever, and connecting means connecting said bushing adjustably to said pivot shaft in parallel axial relationship therewith such that oscillatory motion of said other arm is selectively transferred to said thread layer.

4. The device claimed in claim 3 wherein said connecting means includes an eccentric stud on the top end of said vertical pivot shaft, said bushing having a split clamp extending laterally therefrom and movably accommodating said stud.

References Cited in the le of this patent UNITED STATES PATENTS 1,060,526 Berger Apr. 29, 1913 1,280,680 De Voe Oct. 8, 1918 1,961,270 Weis et al. June 5, 1934 

